There are seven major project areas in which work is being done. Each project area has several subprojects. The major project areas are: 1) Physiological and clinical results of coronary arterial surgery; 2) Intraoperative studies of aorto-coronary bypass surgery; 3) Abnormalities of myocardial contractility in coronary artery disease; 4) Myocardial metabolic studies; 5) Coagulation studies; 6) Study of bilateral bundle brach block; and 7) Incidence and rate of progression of coronary atherosclerosis.